General Troubleshooting 2
5977B Series MSD Troubleshooting and Maintenance Manual 55
Difficulty with the HED supply
The only time this error occurs is if the output of the supply cannot get to its
destination (the HED).
• Large peak, such as the solvent peak, eluted while the analyzer was on
• Pressure in the analyzer chamber is too high
• Detector is not working correctly
• MSD electronics are not working correctly
Difficulty with the high vacuum pump
In an MSD with a turbo pump, this indicates the pump failed to reach 50% of
full speed within 7 minutes, or experienced a fault.
You must switch the MSD off and back on to remove this error message. The
message will reappear if the underlying problem has not been corrected.
• Large vacuum leak is preventing the turbo pump from reaching 80% of full
speed
• Laboratory temperature is too high (generally above 35 °C)
• Foreline pump is not working correctly
• Turbo pump is not working correctly
• Turbo pump controller is not working correctly
• MSD electronics are not working correctly
High foreline pressure
• Excessive carrier gas flow (typically > 5 mL/min)
• Excessive solvent volume injected
• Large vacuum leak
• Severely degraded foreline pump oil (standard foreline pump)
• Collapsed or kinked foreline hose
• Foreline pump is not working correctly
Internal MS communication fault
• MSD electronics are not working correctly